A transport study of W(VI) ions across tri-n-octylamine (TOA) xylene-based supported liquid membranes from aqueous solutions containing tartaric acid (TA) has been carried out. TA complexes with W(VI) ions to keep them in solution and enhance flux. The optimum conditions of transport found are 0.132 M TA and 0.001 M HCl in the feed, 3.7 M NaOH in the strip, and 0.66 M TOA in the membrane. Beyond these TA and TOA concentrations, there is a decrease in flux and permeability values which are 4.76 x 10(-5) mol/m(2) . s and 9.15 x 10(-10) m(2)/s, respectively. NaOH is a better stripping agent than NH4OH for these metal ions. Increases in membrane phase viscosity and temperature reduce the values of these transport parameters.